Closed cycle fish rearing system



Jan 7,21964 H. s. oGDEN ETAL cLosED- CYCLE FISH REARING SYSTEM Filed Oct. 19, 19,62

INVENTORS #Jef/efr .5. 0605/14 BY :nm/Ey 0. @GDE/v lllJ o NN om United States Patent O 3,116,712 CLGSED CYCLE lllSlli PURARWG SYSTEM Hubert S. (lgden and Stanley Dee @gd-en, both or" i214 Santa Monica Blvd., Los Angeles 29, Calif. 'Filed Get. 19, 1962, Ser. No. 231,701 5 Claims. (Cl. 1119-3) This invention relates generally to a closed cycle tisn rea 'ng system and, more particularly, to such a system incorporating improved water purication and circulation means rendering ythe system `Suitable for the rearing and holding of tro-ut and other fresh water lish.

in the past, it has always been necessary to locate trout and other fish hatcheries near an abundant supply or" Jfresh, clean water having the proper temperature and correct physical and chemical properties.

Enormous amounts of Water are presently being used by niost hatcheries since this Water llows through their basins and then is usually discharged as waste without being reused or recovered. Since the quality and quantity of available water can suddenly change without Warning, such a change may permanently damage the existing stock 'of fish and in many leases cause a complete shut down or relocation of the entire hatchery.

Therefore, the principal obiect of this invention is to provide a closed cycle fish rearing syst-em wherein the same water is reeirculated continuously throughout the system and is purified through a continuous process whereby all objectionable soils and dissolved toxic matter are removed.

Another object of the invention is to remove or destroy organisms in the water for the purpose of reducing or preventing water-borne infections and diseases iii trie fish.

Another object of this invention is to maintain a high oxygen residual in the water at all times.

A more specific object of this invention is to remove the carbon dioxide, ammonia, uric acid `or urea, chlorine, manganese, nitrates, nitrites and other dissolved materials wir li may be toxic to the iish.

A further object of this invention is to recover the water which is used to backwash the :lter contained in the system.

Still another object of this invention is to provide a selicleaning holding tank for the fish.

A still more specific object or" this invention is to provide the selreleaning iish tank with cleaning means which is actuated by the torce of the water llowing through the system.

Other objects and advantages of this novel closed cycle iish rearing system will become apparent from the following description and accompanying drawing of a preferred embodiment of this invention.

in the drawing:

The gure is a semiecheinatic diagram showing a closed cycle lish rearing system embodying:r this invention.

As wn in the drawing, this closed cycle sh rearing sys-tem includes a punip iti having an inlet l2 which hoods the system 'with water from either of the storage tanks ld and ifea through a pipe l. inlet 12 is also connected via a pipe i9 to a source (not shown) oi fresh water in order to add to the system any water which maybe lost during the removal of Waste material, evaporation, etc.

The outlet i3 of pump iti is connected to a three-way Valve 2h which is normally positioned to permit water to flow through pipes 22 and 24 to another three-way valve 2d Iwhich is initially positioned to allow the water to -ow into the top of a lilter tank 28 via an inlet 3l) thereof.

The water ilows downwardly through filter Ell and exists at the bottom through the outlet 32;. From there, the water is conducted via pipe 34- to a three-Way valve 36 which is normally positioned to conduct the Water through pipe which carries the water up to an air injector lil Mice which aerates the `water iiowing in pipe 38. rl`he injector All has an inlet pipe il which may be connected to a suitable source of air.

The aerate-d Water is then fed to the top of a spray tower 42. rl'he Water is discharged by the spray head lll and falls by gravity through the battles lo which break the Water into small particles so that they may be saturated with air forced through the particles by a large volume blower titl, The large volume of air saturates the Water with oxygen and at the same time helps to dissipate any excess amount of carbon dioxide which Imay be dissolved in the water. The aerated Water is then collected in a tank 5'@ above which is mounted a chemical feeder 52 of ythe drip type which adds non-toxic chemicals to the Water tank Si@ in order to kill harmful bac eria and decontaniinate the water.

The water in tank iiovvs by gravity via pipe 5d to another tank 5o. Actually, tank 55 is located below tank 5d Within an enclosure 57 even though in order to conserve space and provide greater detail in the dra-wing, the tank 56 is shown at a higher level than tank 5d.

Mounted about tank is an ultra-violet JLamp 5S for irradiating the water within the turk. This ultra-violet radiation maintains a practically sterile condition in the -ith and development of harrnful bacterial cont niiiation. The ultra-violet radiation also helps break doi/vn the organic byproducts or" the sh into removable and compounds.

A heat exchanger including a refrigeration unit 69 located outside enclosure 57' and a cooling coil 62. located in tank maintains th water the proper temperature.

The water in tank 56 ilo-ws by gravity through a pipe of: 1w :ich divides into two pipes on and o3 which iced ws to a fish rearing and holding tank 7u. An air injector 67 havitg air inlet pipe 7d a-erates the water in feeder pipe and an air iniector 69 having an air inlet pipe 73s aerates the water in feeder pipe 69. Pipes 65 and 6h enter tank 'ii at diametrically opposite points oi t1 e ltank and inieet the water into the tank substantially tangentially to its circular wall 723. Stich an arrangement imparts a circular motion to the water in ta ik '7b. The bottom 74 ot tank iii is substantially dish-shaped and `has a Iwaste di charge sump in the center thereof. A dump valve lo may be opened to discharge the waste accumulated in the sumo.

Also disposed in the center oi tank "itl is a stand pipe Sil through which the water Si flows when it reaches the top thereof. A generally cylindrical screen 8d is placed around stand pipe and extends slightly thereabove in order to prevent i'ish from entering the stand pipe. Screen S53 is mounted a short distance above the bottom ill of tank 7@ in order to allow solid waste materials to enter sump 7e centrally disposed in the bottom of the tank.

Since the feed pines oe and dit direct Water into tank lli substantially tangentially to the wall 72, rotary motion is imparted to the Water. Such niotion produces the well known eilect of gradual movement of solids to the center of the tank Iii where they iiow under screen 34 into sump 76. In order to accentuate the natural movement of solids in suspension to the center of tank 7&9, a mechanical scrubber S6 is fixed to a vertical shaft SS which is journaled in a bearing plate 9@ to permit easy rotation of the scrubber. Serubber ilo is iitted along its vertical and bottoni sides with sott bristles h2 which press lightly against the inner periphery or" Wall 72 of the tank 7d and also against the bottom M of the tank. The rotary movement of the water in tank 7'@ inipinges against the exposed surfaces of scrubber S6 and force it to rotate, thereby scrubbing the wall and bottom of tank 7l? to aid in the removal ot solid materials.

Water overflowing through stand pipe Si) flows by gravity over a rillling pan 94 into a sump and settling tank Another high volume air blower 9S saturates the falling water with oxygen in the same manner as accomplished by blower 5S. Another chemical feeder 169 of the drip feed type adds additional non-toxic chemical bactericides and decontaminants to the water in tank 26. An outlet 1 2 permits the discharge of waste material from tank 95 when the dump valve 16E/l is opened.

The water in tank 96 flows out through a pipe 105 and fiows by gravity into a circulating pump 165 which pumps the water up to a valve 197 which is positioned to communicate with a pipe 16S* connected to valve 25 which is now in its normal recirculating position so that the water flows through valve 26 into the inlet 3ft of filter tank 2S. Pump 1G and 165 may be mechanically driven by a common means. In actual practice, pump 166 is located at a lower lever than settling tank 96, even though in the drawing pump 196 is shown above tank 96. Periodically, filter 28 must be backwashed in order to remove solids and suspended material which were removed from the water during the normal purification cycle just described. The storage tanks 14 and 14a are used for this backwashing operation.

`In order to operate in the backwash cycle, three-way valve 2S is operated to its second position to provide communication between the pipe 24 and a pipe 110. Of course, with valve Zt in this position, the outlet of pump 1@ no longer communicates with pipe 24. However, another valve 112 is positioned so that the outlet of pump 19 is connected via a pipe 114 and valve 112 through -a pipe 116 to the three-way valve 36 which is also now turned to its second position so that pipe 116 communicates with the filter outlet 32 via pipe 34. In other words, water is now circulated by pump 10 in the reverse direction through filter 23. Valve 112 also has a position which allows waste to be discharged via a pipe 113.

This backwash water dislodges the solid materials held in the filter' elements of filter 23 and is pumped out of the filter inlet 3) and through to the three-way valve 26 which has also been moved to a second position so that inlet 30 communicates with pipe 24. It can be seen therefore that in this backwash cycle the water flows in the reverse direction through filter 23 by entering the outlet 32 and exiting through inlet 3@ from where it is pumped through pipe 2d, valve 2t? and pipe 11G to a three-way valve 117. In one position of valve 117, water iiows through a pipe 112 into tank 14 and in the other position, through a pipe 112:1 into tank 14a.

In order to quickly settle out the suspended matter which is present in the backwash water contained in tank 14, for example, and also to sterilize this water for further usage, heavy doses of chlorine are first added, followed by an alum solution to form a flock which settles rapidly carrying the suspended matter down into the conically shaped bottom 118 of tank 14.

After the water has been so treated, the necessary valves are returned to their normal positions and the purified water is returned to the system by being pumped through pipe 122, another three-way valve 124 and pipe 18 to the inlet 12 of pump 1 (1.

The storage tank 14a may be alternated with storage tank 14 by operating three-way valve 117 to its alternate position so that pipe 110 communicates with pipe 112a instead of with pipe 112. The backwash is then pumped to storage tank 14a, is treated, and then is recirculated through pipe 122a and valve 124 which is now positioned to permit water to fiow from pipe 122a through pipe 18 to the inlet 12 of pump 10.

Outlets 126 and 12611 are provided in the bottom of the tanks 14 and 14a, respectively, which are provided with corresponding dump valves 128 and 12841 in order to permit the suspended solid material to be emptied periodically from the storage tanks.

During the repeated cycling of the water through the system, the water may become highly contaminated due Sie.

to the presence of fecal matter, urine and decomposed food particles, thereby resulting in highly contaminated water which may be toxic to the fish.

By the combined use of ultra-violet radiation, a catalyst and suitable chemical additives, such material may be precipitated from the water.

By feeding a low solubility calcium solution into the system, irradiating the water with high intensity ultraviolet lamps, aerating the w-ater excessively, and using a suitable catalyst in filter 2S, ammonia, nitrogen, and nitrite nitrogen products may be continuously removed as insoluble precipitates.

There has been described a novel closed cycle fish rearing system which provides a completely closed system of operation and purification of the water used for fish rearing or holding, whereby this same water is recirculated continuously and is purified through a continuous process so that all objectionable solids and dissolved matter are continuously removed with sufiicient rapidity to prevent toxicity in the fish.

Various modifications and improvements in the preferred embodiment of a novel closed cycle fish rearing system as just described will be apparent to those skilled in the art and are considered to be within the purview of this invention, the scope of which is intended to be limited only as defined in the appended claims.

What is claimed is:

1. A closed cycle fish rearing and water circulation system comprising:

(a) pump means for circulating water through said system,

(b) mechanical filter means connected to said pump means,

(c) `a spray tower connected to said mechanical filter means,

(d) means for irradiating with ultra-violet light the water flowing from said spray tower,

(e) a fish rearing tank for holding the irradiated water,

(f) overflow means associated with said fish tank,

(g) a settling tank for holding overflow water from said fish tank including a bottom,

(lz) means therein for removing sediment from said ysettling tank,

(i) means for feeding the water in said settling tank to said mechanical filter means,

(j) means for aerating the water fiowing through said system, and

(fr) means for adding a chemical bactericde to the water flowing through said system.

2. A closed cycle fish rearing system as defined in claim 1 wherein said fish tank has a generally circular wall and a dish-shaped bottom and further comprising conduit means for feeding the irradiated water into said fish tank substantially tangentially to said wall.

3. A closed cycle fish rearing system as defined in claim 2 further comprising scrubber means rotatably mounted within said fish tank and actuated by the force of the water entering said tank through said conduit means.

4. A closed cycle fish rearing and water circulation system comprising:

(a) a first pump for circulating water through said system and having first and second inlets and an outlet,

(b) a filter having an inlet and an outlet,

(c) first conduit means connecting said pump outlet to said filter inlet,

(d) a spray tower,

(e) second conduit means interconnecting the outlet of said filter and said spray tower,

() means to inject air into water fiowing through said second conduit means,

(g) a first tank associated with said spray tower, the water fiowing by gravity through said tower into said first tank,

(h) means to blow air through the water falling through said tower,

(i) means for adding a chemical de-contaminant to said first tank,

(j) a second tank connected to said lirst tank so that water iiows by gravity from said iirst to said second tank,

(k) an ultra-violet lamp mounted above said second tank for irradiating the Water contained therein,

(l) means for cooling the water contained in said second tank,

(m) a fish rearing tank,

(n) third conduit means for allowing water to ilow by gravity from said second tank to said sh rearing tank,

(o) means to inject air into the water flowing through said third conduit means,

(p) an overfiow pipe in said fish tank,

(q) a screen surrounding said overfiow pipe,

(r) valve means for removing sediment from the bottom of said fish tank,

(s) a sump and settling tank disposed beneath said fish tank so that water flows by gravity through said overow pipe to said sump and settling tank,

(t) means for blowing air through the water flowing into said sump and settling tank,

(u) means for adding a chemical de-contaminant to said sump and settling tank,

(v) valve means for removing sediment from the bottom of said sump and settling tank, and

6 (w) a second pump for pumping water from said sump and settling tank to said inlet of said filter. 5. A closed cycle fish rearing system as defined in claim 4 further comprising:

(a) a valve means for connecting said iirst pump outlet to said filter outlet to force backwash water in the reverse direction through said filter to said filter inlet,

(b) a backwash water storage and treatment tank,

(c) valve means connected between said filter inlet and said storage tank for directing backwash water to said storage tank, and

(d) valve means for removing sediment from the bottom of said storage tank.

References Cited in the file of this patent UNITED STATES PATENTS 1,121,394 Patten Dec. 15, 1914 1,248,169 Schnoor Nov. 27, 1917 1,608,019 Fender Nov. 23, 1926 1,794,841 Elreth Mar. 3, 1931 1,873,594 Johnson Aug. 23, 1932 2,198,124 McGill Apr. 23, 194() 2,491,645 Clark et al. Dec. 20, 1949 2,594,474 McGrath Apr. 29, 1952 2,672,845 Schneithorst Mar. 23, 1954 2,795,288 Hirs June 11, 1957 2,944,513 Keely July 12, 1960 3,025,831 Berardi Mar. 20, 1962 

1. A CLOSED CYCLE FISH REARING AND WATER CIRCULATION SYSTEM COMPRISING: (A) PUMP MEANS FOR CIRCULATING WATER THROUGH SAID SYSTEM, (B) MECHANICAL FILTER MEANS CONNECTED TO SAID PUMP MEANS, (C) A SPRAY LOWER CONNECTED TO SAID MECHANICAL FILTER MEANS, (D) MEANS FOR IRRADIATING WITH ULTRA-VIOLENT LIGHT THE WATER FLOWING FROM SAID SPRAY TOWER, (E) A FISH REARING TANK FOR HOLDING THE IRRADIATED WATER, (F) OVERFLOW MEANS ASSOCIATED WITH SAID FISH TANK. (G) A SETTLING TANK FOR HOLDING OVERFLOW WATER FROM SAID FISH TANK INCLUDING A BOTTOM, (H) MEANS THEREIN FOR REMOVING SEDIMENT FROM SAID SETTLING TANK, (I) MEANS FOR FEEDING THE WATER IN SAID SETTLING TANK TO SAID MECHANICAL FILTER MEANS, (J) MEANS FOR AERATING THE WATER FLOWING THROUGH SAID SYSTEM, AND (K) MEANS FOR ADDING A CHEMICAL BACTERICIDE TO THE WATER FLOWING THROUGH SAID SYSTEM. 